Decentralized Power Plants Research Articles

Techno-Economic Performance and Sensitivity Analysis of an Off-Grid Renewable Energy-Based Hybrid System: A Case Study of Kuakata, Bangladesh

Hybrid renewable energy sources (HRES) are increasingly being utilized to meet global energy demands, particularly in rural areas that rely on diesel generators and are disconnected from the utility grid, due to their environmental and human health benefits. This study investigates the performance of an off-grid, hybrid PV/diesel generator/battery system for a decentralized power plant in Kuakata, Bangladesh, meeting a load demand of 3000 kWh/day with a 501.61 kW peak load demand. HOMER Pro (hybrid optimization model for electric renewable) software (version 3.11) was used to simulate and optimize system operations utilizing real-time solar radiation and load profile data from that location. This study also includes a sensitivity analysis of the off-grid HRES system under different electrical load demands, project longevity, and derating variables. The results reveal that CO2 emissions have potentially decreased by more than 30% and over 10 tons per year, respectively, when compared to traditional power plants. The optimized system’s net present cost (NPC) was determined to be around USD 5.19 million, with a cost of energy (COE) of USD 0.367 per kWh per unit with a 100% renewable component. Furthermore, the current study’s findings are compared to previous research that has resulted in an economical hybrid renewable energy system with an affordable COE. The hybrid energy system under consideration might also be applicable to other parts of the world with comparable climate conditions.

AI Enabled Crypto Mining for Electric Vehicle Systems

A virtual grid (VG) is an interconnected system that includes a decentralized power plant, flexible loads, and energy storage facilities. During peak demand, a VG can distribute the power provided by several interconnected units in an equitable manner, ensuring that the grid burden is spread out evenly. Electric vehicles (EVs) and other demand-side energy devices can help keep the energy market supply and demand in harmony with proper use. However, it might be difficult to maintain a consistent power balance due to the inherent unpredictability of the power units. Furthermore, the issue of protecting the privacy of communications between a VPP aggregator and the final facilities has not been thoroughly explored. In this paper, we provided detailed analytics on optimization-based crypto mining for electric vehicle systems. The simulation is conducted to test the efficacy of the model, and the results show that the proposed method has a higher rate of accuracy than other methods.

Dynamic Overlapping Coalition Formation in Electricity Markets: An Extended Formal Model

The future power system will be characterized by many small decentralized power plants—so-called distributed energy resources (DERs). The integration of these DERs is vital from an economic and grid operation point of view. One approach to this is the aggregation of such DERs. The formation of coalitions as an aggregation method has already been examined in the literature and applied in virtual power plants, active distribution networks, and microgrids. The spread of DERs also increases the need for flexibility and dynamics in the power grid. One approach to address this can be overlapping coalitions. Therefore, in this paper, we first performed an analysis of related work and, in this context, found no work on overlapping coalitions for energy use cases in the literature. We then described a method for dynamic coalition formation, called dynamic coalition in electricity markets (DYCE), and analyzed how DYCE would need to be extended to include overlapping coalition formation. The extension includes the phases of product portfolio optimization and the actual coalition formation. Our analysis of DYCE shows that the methods used for the optimization of the DYCE sub-tasks are not suitable for overlapping coalitions and would have to be replaced by other methods in order to be able to form overlapping coalitions.

A Multidisciplinary Approach for an Effective and Rational Energy Transition in Crete Island, Greece

This article proposes a mixture of actions for the development of an effective and rational energy transition plan for all sectors and for all types of onshore final energy use in Crete. Energy transition is initiated with an appropriate capacity building campaign. The plan is based on the introduction of energy saving measures and the exploitation of all the locally available energy resources (wind, solar, geothermal potential, biomass), integrated in a cluster of centralized and decentralized power plants and smart grids to produce electricity and heat and for the transition to e-mobility. The core of the energy transition in Crete will be a set of 14 wind parks and Pumped Hydro Storage systems (PHS) for electricity generation and 12 Combined Heat and Power plants, properly designed and dispersed in the insular territory. Economic analysis is executed for the proposed essential power plants on the island. Biomass, solar and geothermal potential can cover the heating demand in Crete several times. Heat can be produced with a specific cost of 0.05 EUR/kWhth from cogeneration plants fired with solid biomass and biogas. The wind parks-PHS systems exhibit payback periods of approximately 10 years with a final electricity selling price at 0.12 EUR/kWhel. The article shows that 100% energy transition in Crete constitutes a feasible target.

Biogas as an alternative source of decentralized bioelectricity for large waste producers: An assessment framework at the University of São Paulo

Decentralized power plants fueled with biogas from organic waste are a keystone for large waste producers responsible for their waste management to reduce the impact of waste generation and poor management, especially in the urban centers, alongside bioenergy and other value-added products generation. This work presents an assessment framework for the characterization quantification and assessment of the biogas potential using theoretical and lab-scale methodologies to evaluate the technical and economic bioelectricity potential from biogas using the organic residues and effluents produced in the main USP campus. The yearly costs to transport and dispose of these residues are around US$ 3,253,716.25, and the electricity consumption is about 8.6 million US$/y. As a large generator, USP is responsible for its residue management, and reduce its generation by the local use to produce bioelectricity is a feasible option. The results show a biogas potential up to 2,363,405.15 m3, allowing for a bioelectricity generation of up to 4454 MWh/y. A potential to produce 3081.131 tones of dry biofertilizer was also estimated. The wasted resource could currently supply up to 5.6% of the Campus's electricity demand, with an investment of around US$ 1.5 million and a payback range between 3.64 and 7.5 years.

Microgrid Optimum Identification Location Based on Accelerated Particle Swarm Optimization Techniques Using SCADA System

The microgrid has become significant and commonly used; it has localized electricity sources and loads connected to a centralized electrical power network system when the need arises and disconnects to island mode. A microgrid can effectively be integrated with various distribution generators, which can improve the voltage level on the transmission line by reducing the real power losses. In this work, new technologies will permit power grids to be better prepared for future requirements. The numbers and diversity of such decentralized power plants require a new type of management in the operation of power grids and intelligent networks or “smart grid.” A SCADA system will improve coordination between power demand and generation and use of modern information technology such as the internet, sensors, controllers, and wireless transmission equipment and use smart metering. The Accelerated Particle Swarm Optimization technique will be used to select the optimum location of a wind turbine to install in the power grid considering minimum power losses with optimal operation consideration of the number of iterations, the execution time of the program, and the memory capacity. The analysis and the study are carried out in MATLAB and the SCADA system.

Multi-criteria optimization for the design and operation of distributed energy systems considering sustainability dimensions

The growing concerns about climate change and energy security have led to a shift in the paradigm of the energy framework. In this regard, distributed generation offers the possibility to deal with inefficiencies in energy delivering, and the fossil fuel dependence of conventional and centralized power plants. This work presents a modeling and multi-criteria optimization strategy for designing and operating decentralized power plants including different energy vectors. The modeling approach considers the time-varying operation of the energy conversion units for responding to electricity and hydrogen demands, along with the seasonal behavior of the storage system. A multi-criteria evaluation addressing economic, environmental and social aspects was implemented. The objective functions are the total annualized cost, the CO2 emissions and the grid dependence. According to optimization results, it is highlighted the influence of the assessed criteria upon the structure and the operating policy of the power plant. Additionally, by comparing the performance of the distributed energy system with respect to a centralized scenario, it is noted the significant potential of the decentralized generation. Indeed, depending on the optimization goal, CO2 emission reduction up to 89%, and self-sufficiency up to 81% can be achieved.

Study of low head turbine propellers axial flow for use of micro-hydropower plant (MHP) in Aceh, Indonesia

Low head hydropower has the potential to produce green energy with a minimum on the environment and is one of the best choices for decentralized power plants. Aceh is one of many regions in Indonesia with hilly topography and many river streams. Of the 66 rivers in Aceh that have potential energy sources that can be developed 98.5 percent are low head. Generally, the technique for overcoming altitude problems in low river flows is the use of low head turbines. An important aspect of head power generation techniques is the selection of turbines. The study aimed to study low head propeller turbines for the use of micro hydropower plants. By calculating the main dimensions and main components of the turbine, field experiments were carried out to determine turbine rotation and energy, as well as turbine efficiency at a flow rate of 0.06 m3/sec and a 3.5-meter head. The calculation results obtained by a specific turbine speed of 1.53, runner diameter of 0.30 meters, hub diameter of 0.06 meters, shaft diameter 0.03, runner length 1.08, triangular speed of 30 degrees with the number of blades 4 pieces. From the results of field experiments, the maximum turbine rotation speed is 1828 rpm, the turbine power is 2,530 watts with a voltage between 220 to 240 volts while the maximum efficiency is 57 percent. It can be concluded that propeller-type turbines with the low head are suitable for micro power plants, especially in remote areas.

Steady transonic dense gas flow past two‐dimensional compression/expansion ramps revisited

AbstractSupersonic flow past compression/expansion ramps represents a canonical problem in fluid dynamics which has been studied extensively in the past assuming perfect gas behaviour. More recently real gas effects on such flows have received increasing attention as part of efforts, among others, to increase the efficiency of Organic Rankine Cycles for decentralized power plants. Of special interest in this connection are dense gases of Bethe–Zel'dovich–Thompson fluids which have the distinguishing property that the so called fundamental derivative of gasdynamics Γ takes on negative values in the general neighbourhood of the thermodynamic critical point. Asymptotic analysis of the transonic flow regime has so far concentrated on cases where the unperturbed state with pressure p0, density ρ0 and entropy s0 is close to the transition curve Γ = 0 in the pressure specific volume plane such that |Γ0| ≪ 1, , Kluwick and Cox [1], [2]. These studies have revealed a number of new phenomena and a non‐uniqueness of solutions exceeding that known from the theory of perfect gases.Here we extend the analysis to cover flows where the unperturbed state in the p, 1/ρ plane is in the vicinity of the point on the transition line where Γ and Λ vanish simultaneously. Such flows have |Γ0| ≪ 1, |Λ0| ≪ 1, and are of considerable practical interest as isentropes that can be realized experimentally at present just barely enter the negative Γ region. Again an increased wealth of possible solutions is observed.

Energy 4.0: Towards IoT Applications in Kazakhstan

The IoT is emerging as one of the most novel regulated approaches towards the future smart and green energy system. The Inter- net of Things combined with the energy management can make an efficient future with reduced costs and improved performance. IoT technologies are used in power grids to improve the performance of traditional power grids and increase their flexibility and reliability. The combination of IoT and power grid is known as a smart grid. The main concept behind smart grid is the distributed generation. Contrary to the conventional grids, distributed generation introduces small and decentralized power plants allocated near or at the end-user location. This paper discusses the existing applications of IoT technology in power industry and analyzes their possible implementations in Kazakhstan. Considering low urbanization level and low population density of KZ, the potential of IoT implementation in energy sector of country is promising. In the paper we are presenting the possible applications of the IoT in the energy sector of Kazakhstan: its future potential, benefits and the challenges and problems that are related with the adoption of Energy 4.0. A novel regulated MAS approach for the energy market as well as online power lines monitoring is presented.

Performance prediction of a decentralized power plant (120 kWe) using a multi-particle model of a downdraft biomass gasification process

A one-dimensional model of a downdraft biomass gasifier is presented to investigate the effect of operating parameters on the performance of a power plant. The approach considers the biomass fed to the reactor by employing discrete particle size distribution (DPSD) to simulate the real operational conditions of a gasification power plant (120 kWe/400 kWth). Char production (byproduct) and producer gas (PG) flow are the targets of the model; the model has been validated using data from an industrial power plant (biomass consumption, pressure drop, and PG composition) with an average relative error of 1.8%. The model achieved stable and reliable results using DPSD for 16 different particle sizes. The increase in the mean biomass particle diameter (15–60 mm) diminished the PG power (363.8–285.3 kW) and the cold gas efficiency (CGE) (63.2–54.36%) because of low particle surface/volume ratio. When biomass moisture content increased (5–25 wt%), the PG power decreased (364.14–318.75 kW) because of low gasification temperature. Moreover, when the number of driven engines was increased from 2 to 5 (electric power), the CGE decreased (68.17–59.17%) due to the low residence time of the solid and gas phases, which inhibited the gasification reactions, in the reactor.

Weak shock reflection in steady transonic dense gas flow

AbstractFlows of dense gases may exhibit a number of phenomena which are impossible in the case of perfect gases and thus are of considerable theoretical interest. These include, among others, the formation of rarefaction shock waves which accelerate rather than decelerate the gas and a substantial increase of the lower critical Mach number. As a consequence there is no danger of flow separation if rarefaction shocks interact with boundary layers in high Reynolds number flow. Experimental work is needed to clarify whether these phenomena predicted by theory can be realised in a technical environment and be used to increase the efficiency of turbomachines in Organic Rankine Cycles for decentralised power plants in low popularised areas. Special interest here is for steady transonic flow. The present work is intended to support such experimental efforts. As a first step the most simple but canonical case of slightly supersonic flow past compression/compression ramps was considered in Kluwick & Cox [1]. The present study is intended to complete the understanding of such flows by investigating the reflection problem arising from the presence of an opposing solid wall in confined geometries.

Repetitive Pitch Control for Vertical Axis Wind Turbine

Increasing demands in decentralized power plants have focused attention on Vertical Axis Wind Turbines (VAWTs). However, accessing high range of power from VAWTs is an impediment due to increased loads on the turbine blades. Here, we derive an optimal pitching action that reduces the periodic disturbance on turbine blades of VAWTs without affecting their power production. A control technique called Subspace Predictive Repetitive Control (SPRC) alongwith a LQ Tracker is used for recursive identification to estimate the parameters of VAWT model and further provide an optimal control law accordingly. Basis functions have been used to reduce the dimensionality of the control problem. Simulation results show a great potential of the data-driven SPRC approach coupled with LQ Tracker in reducing the turbine loads on VAWTs.

Challenge of retrofitting old decentralised power plants in Germany in terms of power system stability

In order to counter the danger of instabilities caused by old decentralised power plants, the Ordinance on System Stability (Systemstabilitätverordnung, SysStabV) was implemented in Germany in June 2012. This study describes the process including tasks and responsibilities of all relevant stakeholders within the second stage of implementing the SysStabV. In contrast to its first stage, power plant operators have the option to apply for proportional reimbursement as well as for exemption from the obligation of retrofitting measures for their power generation plants. Strangely it has been stated that the actual number of applied exemptions is much lower than the expected one. Furthermore, also the number of confirmed retrofitting is lower than expected. In conclusion, a considerable divergence between the forecast and the actual state data indicates the importance for an on-site inspection at power plants as part of an important follow-up process.

Determination of Optimized Parameters for the Flexible Operation of a Biomass-Fueled, Microscale Externally Fired Gas Turbine (EFGT)

Biomass as a source of renewable energy is a promising solution for current problems in energy supply. Olive waste is considered as an interesting option, especially for Mediterranean countries. Within this paper, a microscale externally fired gas turbine (EFGT) technology is presented as a decentralized power plant, within the range of 15 kWth, based on olive residues. It was modeled by Aspen Plus 8.6 software to provide a sufficient technical study for such a plant. Optimized parameters for pressure ratio and turbine air-mass flow have been mapped for several loads to provide information for process control. For all cases, mechanical output, efficiency curves, and back-work ratio have been calculated. Using this information, typical plant sizes and an example of power production are discussed. Additionally, achievable energy production from olive waste is estimated on the basis of this data. The results of this study show that such a plant has an electrical efficiency of 5%–17%. This variation is due to the examination being performed under several combustion temperatures, actual load, heat exchanger temperatures, and heat transfer efficiency. A cost estimation of the discussed system showed an estimated capital cost of 33,800 to 65,300 € for a 15 kWth system.

Thermodynamic methodology to support the selection of feedstocks for decentralised downdraft gasification power plants

ABSTRACTThermodynamic criteria as a feedstock selection tool for decentralised downdraft gasifiers coupled to spark-ignition engines are presented in this work. The methodology consists of an energy and exergy analysis of gasification process. The analysis is carried out by computational modelling of the gasification process as a function of biomass type (ultimate analysis, moisture content and heating value) and fuel/air ratio. Considering a system operating with different wood species, analysed parameters are gas heating value, energy and exergy efficiencies and engine fuel quality (EFQ). With a fixed fuel/air ratio (2.6) and moisture content (20%wt), it is highlighted that as the carbon-oxygen molar ratio of wood decreases from 2.0 to 1.78 as model input, reaction temperature increases by 9%, energy and exergy efficiencies diminish by 1.8% and 4.2%, respectively, while EFQ increases by 3.2%. Therefore, for decentralised power plants, biomass should be selected to produce higher EFQ.

Enhancing viability of biofuel-based decentralized power projects for rural electrification in India

Decentralized power generation, using locally available biofuels from non-edible oilseeds, is an option for rural electrification in many developing countries. However, due to prevailing high price of non-edible oilseeds, such as Jatropha curcas, the cost of electricity generation is very high. This paper provides detailed financial analysis of straight vegetable oil (SVO)-based decentralized power project and proposes an innovative model for enhancing their financial viability. While for implementing agency operational cost recovery is the key for viability, affordable tariff is crucial for end-users. The paper attempts to estimate minimum desired price of electricity from the stakeholders' (producer and users) perspective using data gathered from selected operational SVO-based power generation projects in India. Analysis carried out in this paper indicates that operating the decentralized power plant at higher capacity utilization factor, by introduction of productive load, and differentiated tariffs for commercial and domestic consumers may not alone be sufficient to achieve the financial viability. The paper proposes an innovative integrated model of using biogas, obtained from the by-product de-oiled cake of non-edible oilseeds, as a feedstock for power generation, instead of using the SVO in engines. This reduces the fuel cost of power generation, thereby helping to bring down the tariff within the paying capacity of rural consumers. The main produce, viz. extracted non-edible oil, which was otherwise used as fuel for generating power, can be sold in local market for earning revenue, thereby enhancing the project’s economic viability. This paper sets forth the proposed integrated model as a viable biofuel-based decentralized power project for sustainable rural development in areas with adequate availability of oilseeds.

Burning of Crop Residue and its Potential for Electricity Generation

This paper identified the factors influencing the rice crop residue burning decision of the farmers and the potential of the burnt residue to generate electricity. For this study, data were collected from 400 farmers in the rice-wheat cropping system. Effects of different variables on the burning decision of rice residue are investigated through logit model. A number of factors had significant effects on the burning decision of crop residue. These included farming experience of the farmer, Rajput caste, farm size, owner operated farm, owner-cum-tenants operated farm, silty loam soil type, livestock strength, total cost associated with the handling of residue and preparation of wheat field after rice, availability of farm machinery for incorporation, use of residue as feed for animals, use of residue as fuel, intention of the respondent to reduce turnaround time between harvesting of rice and sowing of wheat, convenience in use of farm machinery after burning of residue and the geographic location of farm. The overall quantity of rice straw burnt is estimated to be 1704.91 thousand tonnes in the rice-wheat cropping areas with a potential to generate electric power of 162.51 MW. This power generation from crop residues would be a source of income for the farmers along with generation of additional employment opportunities and economic activities on sustainable basis. In order to minimise the cost of haulage of rice straw, installation of decentralised power plants at village level would be a good option. Further, use of rice crop residue as an energy source can help in reducing foreign exchange requirements for import of furnace oil. JEL Classification: O44, Q12, Q16, Q42, Q48 Keywords: Bioenergy, Crop Residue, Electricity, Energy, Growth, Rice

Husk Power Systems: Bringing Light to Rural India and Tapping Fortune at the Bottom of the Pyramid

Lighting over 200 villages through de-centralized power plants, impacting 200,000 people’s lives and counting - Acumen Fund. Although the rapid growth of the Indian economy in the last two decades has brought prosperity to a large segment of its population, thereby leading to higher living standards, there still remain some dark spots that cast doubts on this success story. There are still many remote parts of the country which are deprived of power supply owing to lack of regular supply of electricity through normal grid connections. This scenario changed with the launch of Husk Power Systems (HPS), which was initiated after a conversation between two friends, Gyanesh Pandey in Los Angeles, United States of America (USA), and Ratnesh Yadav in Patna, Bihar, India, and their strong desire to bring change to rural India. After several attempts over five years, to generate power through various biodiesel resources, they settled on rice husk as a source for generating electricity. Husk Power Systems was started in 2007 and today, they have already lit up more than 200 villages with a typical power plant by HPS catering to around five villages depending on the number of households. Currently, they can provide power for up to 12 hours a day, which can be scaled-up to an uninterrupted 24 hour power supply. The challenge here is that there is no current demand for 24 hour power supply in remote villages where people have just started realizing the benefits of electricity and don’t feel the need for continuous power, and also don’t have adequate finances to pay for it. While working on scaling-up their business, the issue which is bothering them most is how to encourage villagers to increase their power consumption to 24 hours a day instead of just 6 hours a day.

IGCC–EPI: Decentralized concept of a highly load-flexible IGCC power plant for excess power integration

The growing share of renewable energy generation eventually could lead to increased fluctuations in power supply and to negative residual loads. Therefore flexible power plants as well as significant long-term energy storage capacity are required. In this paper, an Integrated Gasification Combined Cycle (IGCC) power plant is combined with an electrolysis plant and substitute natural gas (SNG) synthesis. In this way a highly load-flexible IGCC plant is developed for excess power integration (EPI) from renewable energy sources or inflexible conventional power plants. The proposed IGCC–EPI concept is modeled in Aspen Plus. The decentralized power plant has a capacity of 125MWth and runs on hard coal. An extensive parameter study has demonstrated the superior operation range from +67MW to −253MW of net power output/input. Synergies between the IGCC–EPI power plant, the methanation process and the electrolysis indicate a maximum overall efficiency of 40.1% from coal and excess energy to SNG and back to electricity.